This advice is almost exactly the opposite of "good". You might be interested to learn that James Dobson, of Dobsonian fame, specifically designed the telescope to be simple to construct and use. The OP talked about the moon and Saturn. Both of those objects are very easy to see with the naked eye, and therefore very easy to point an alt-azimuth telescope at. An equatorial mount or motor drive is actually harder for a beginner to use than just a simple push-to-go-to alt-az mount. And any motorized drive you could get for anywhere near $100 is just junk.

All that said, you probably won't find a new Dobsonian scope for $100. There are some inexpensive alt-az refractors for about $120 - the Orion StarBlast 70mm for example. It has a finderscope, an erect-image diagonal, and a standard 1.25"-diameter focuser and two eyepieces. Might be worth a peek.

Alternatively, if you are interested in really learning a lot about telescopes, you could build one, starting with grinding your own mirror. You might get that done for about $100 for a 4.25" reflector.

If I were personally going to use one of Tesla's patents in my business, I'd want a signed zero-cost GPL-like license agreement with Tesla. For example, Musk's good will is nice, but what if someone else were to acquire Tesla's IP?

Eris is just 2326 kilometers across—possibly smaller than Pluto, whose diameter is somewhere between 2300 and 2400 kilometers. The uncertainty arises because Pluto, unlike Eris, has air that complicates the interpretation of observational data.

cunniff writes: Remarkable statistics from the Keck Observatory on Mauna Kea, Hawaii — 22% (+/- 8%) of stars have an Earth-sized planet in its habitable zone. From the press release, UC Berkley graduate student Erik Petigura says, "What this means is, when you look up at the thousands of stars in the night sky, the nearest sun-like star with an Earth-size planet in its habitable zone is probably only 12 light years away and can be seen with the naked eye. That is amazing,"

This, of course, raises the Fermi paradox again — if alien life is common, why haven't we seen it yet? This study will be used to spark further investigation, including proposals for space telescopes which might be able to image nearby Earth-sized planets.Link to Original Source

The university is welcoming four renowned curators from Carnegie Museum into its classrooms to teach seminars and use the museum collection, which is considered one of the world's premiere displays of natural history artifacts, for demonstrations. Included in the collection is a 150-million-year-old fossilized dinosaur bone complete with a tumor.

I would not be surprised if there are even older amphibian tumor fossils out there somewhere.

Possibly the most exciting physics news of the year. Although the detection of the Higgs boson was big, it mostly confirmed what existing theory predicted. Interesting, important - but, to some physics, perhaps a bit boring.

If further measurements continue to verify this effect, there are some very interesting new physics to discover.